Moved css from js file to relevant scss file.
Added tests for tabbing through captions
Bug fixes, mainly in tests
Replaced mouseenter and mouseleave event handlers by mouseover and mouseout. The former were failing Jasmine tests. Since the captions are li elements without descendants, they are identical.
Caption have unfocused class as default
Removed unfocused class and set the captions default values of outline-width and outline-style to it.
Merge pull request #1028 from edx/accessibility_duplicates

Fixed duplicate ID attributes in registration & login
edx.org/LMS: reverts a Sass placeholder extend back to a class selector for view reference
Merge pull request #1039 from edx/talbs/fix-lms-contentwrapper

edx.org/LMS: FIX - Reverts Sass placeholder extend back to view-based selector
Merge pull request #933 from edx/jmclaus/bugfix_tabbing_captions

Tabbing through captions
Merge pull request #1032 from edx/adam/a11y

Adam/a11y
Merge pull request #1025 from edx/adam/accessible-tabs

make tooltips screen-readable
Merge pull request #947 from cpennington/group-python-tests

Teach rake to run all python tests as a group
Add ability to run against generic selenium grid
Merge pull request #1036 from edx/zoldak/refactor-static-page-tests

Simplify static page acceptance tests
Studio: Converts all class-based Sass archetype-focused  @extends to use Sass placeholder syntax
Merge pull request #989 from edx/talbs/studio-sassplaceholders

Studio: Switch class-based Sass @extend rules to use Sass placeholder syntax
Merge pull request #930 from cpennington/rename-xblock-field-data

Rename xblock_field_data to xmodule_field_data
Install prereqs before collecting assets
Merge pull request #1044 from edx/zoldak/acceptance-grid

Add ability to run against generic selenium grid